The present disclosure relates generally to a formulation in the form of an emulsion which includes a combination of a gum blend and an electrolyte tolerant polymer, and items using same. The gum blend provides physical stability to an emulsion containing both clay and silicone oil. The emulsion of the present disclosure is useful for rash prevention and may be applied to the skin with a wipe wetted therewith or by other various means.
Wet wipes have been used for years for convenient skin cleansing between diaper changes. Much headway has been made in creating formulations for wet wipes. Such formulations are in the form of emulsions which provide a vehicle for the application of active ingredients to the skin. These ingredients may be used to treat and/or prevent diaper rash.
Diaper rash is a form of contact dermatitis which afflicts infants or incontinent persons whose wet and/or soiled absorbent garments are not promptly changed. Because of the practical impossibility of attending promptly to all of a person's needs, even those receiving a high level of care sometimes suffer from diaper rash. It has recently come to be understood that the initial stages of some types of diaper rash are the result of skin irritation caused by contact with digestive enzymes present in feces, particularly trypsin, chymotrypsin and elastase. These enzymes are proteolytic enzymes produced in the gastrointestinal tract to digest food. Similar conditions conducive to skin irritation by proteolytic enzymes present in feces are found in patients having colostomies. Such patients would also benefit from improved treatments to prevent skin irritation due to fecal enzymes.
Silicone oil is a commonly used active ingredient that acts as a skin barrier to prevent skin irritation. However, sometimes a skin barrier alone is not enough to prevent skin irritation, especially when fecal matter is present. Therefore, it is also desirable to sequester irritants such as proteolytic enzymes away from the skin.
Clay is one substance that can bind the protease enzymes found in fecal matter. Unfortunately, in all practicality, the benefits of clay and silicone oil cannot be realized in the same product due to physical instability. When clay and silicone oil are placed together into a highly aqueous emulsion, the emulsion tends to phase separate. Even without clay, an emulsion with a therapeutic amount (1% to 10% by weight) of silicone oil (e.g. dimethicone) can phase separate.
While there are several methods to achieve stable emulsions with silicone oil at concentrations compliant with its use as an over-the-counter drug, there are several disadvantages associated with these methods. First, the concentration of emulsifier required to successfully stabilize an emulsion containing the silicone oil, e.g. dimethicone, can be so great that it is cost prohibitive. Second, obtaining a low-viscosity, sprayable solution can be difficult due to the high probability that silicone oil droplets will coalesce, particularly at the elevated temperatures to which the solution may be exposed. Third, without appropriately modifying the rheology of the water phase, emulsions with a low viscosity and low solids content tend to undergo phase separation, particularly following a freeze-thaw cycle. This results in a non-uniform product that would not be efficacious.
Accordingly, there is a need for an emulsion that contains silicone oil as an active ingredient and does not phase separate even in the presence of clay. There is a further need to stabilize an emulsion containing silicone oil in a manner that is cost effective. It would be further advantageous if the formulation containing the emulsion and a sequestering solid such as clay would be suitable for spraying onto a substrate during the manufacture of a wet wipe. Additionally, there is a desire to apply preservatives to the emulsion, especially if it is to be applied to a natural substrate (e.g. cellulose) where there is more likelihood of microbe or fungal growth.